This invention relates to a liquid jetting apparatus having a head member capable of jetting liquid from nozzles, such as an ink-jet recording apparatus having a recording head capable of jetting ink from nozzles to form dots on a recording medium. In particular, this invention is related to a liquid jetting apparatus which can prevent viscosity of liquid in nozzles from increasing.
An ink-jet recording apparatus such as an ink-jet printer or an ink-jet plotter has a recording head that is movable along a main scanning direction. The recording head has nozzles capable of jetting ink. For example, the nozzles are communicated to pressure chambers which can expand and contract respectively. In the case, the ink in the nozzles can be jetted by expanding and contracting of the pressure chambers.
On the other hand, the ink-jet recording apparatus is adapted to feed a recording medium such as a paper along a subordinate scanning direction, which is perpendicular to the main scanning direction. Thus, the nozzles of the recording head can jet ink to form an image or a character on the recording medium in cooperation with moving the recording head and the recording medium according to recording data.
The ink in the nozzles of the recording head is exposed to air. Thus, solvent of the ink such as water may gradually evaporate to increase a viscosity of the ink in the nozzles. In the case, quality of printed (recorded) images may deteriorate because the ink having a great viscosity may be jetted toward a direction deviated from a normal direction.
To prevent the viscosity of the ink in the nozzles from increasing, some measures have been proposed. One of the measures is to cause a meniscus of the ink to minutely vibrate to stir the ink. The meniscus means a free surface of the ink exposed at an opening of the nozzle.
For stirring the ink, the meniscus may be vibrated to a jetting direction of the ink and to a contracting direction opposed to the jetting direction by turns in such a manner that the ink may not be jetted. The vibration of the meniscus can be also carried out by expanding and contracting of the pressure chambers. Owing to the vibration of the meniscus, the ink at the opening of the nozzle may be stirred to prevent the viscosity of the ink from increasing.
The stirring of the ink may be carried out during a recording operation. For example, the stirring may be carried out while a carriage carrying the recording head is being accelerated after starting a main scanning, or while a recording operation for a line is being carried out. In the stirring while the carriage is being accelerated, a micro-vibrating operating signal for micro vibrating is supplied to the recording head to cause all menisci in the nozzles to minutely vibrate. In the stirring while the recording operation is being carried out, a pulse signal for micro vibrating is generated from a jetting operating signal for jetting ink, and the pulse signal is supplied to the recording head. Thus, the ink in the nozzles not in the recording (jetting) operation may be stirred.
In addition, Japanese Patent Laid-Open Publication No. 2000-21507 has described that it is effective to cause menisci of ink in nozzles to minutely vibrate during a predetermined time from a suitable timing just before jetting a drop of the ink or from a suitable timing just before jetting a drop of the ink till another suitable timing just before jetting a drop of the ink.
In the conventional ink-jet recording apparatus, micro-vibrating operating signal (including a mid-recording micro-vibrating pulse) supplied to the recording head is constant, independently of a characteristic and/or a kind of the ink. Thus, if a micro-vibrating operating signal is set suitably for ink whose viscosity tends to increase, some problems may arise at nozzles for jetting ink whose viscosity tends not to increase when micro-vibrating operations are performed according to the micro-vibrating operating signal. For example, the nozzles may drip with the ink so that the ink may not be jetted from the nozzles accurately but deflected.
In order to generate a plurality of micro-vibrating signals corresponding to a plurality of characteristics, kinds or states of ink, there is a simple way to provide a plurality of signal-generating circuits. However, the way is not suitable in view of miniaturizing the ink-jet recording apparatus.
The object of this invention is to solve the above problems, that is, to provide a liquid jetting apparatus having a head member capable of jetting liquid from nozzle that can suitable micro-vibrating operations correspondingly to respective characteristics, kinds or states of liquid, such as an ink-jet recording apparatus that can perform suitable micro-vibrating operations correspondingly to respective characteristics, kinds or states of ink.
In order to achieve the object, the invention is a liquid jetting apparatus comprising: a head member having a nozzle, a micro-vibrating unit that can cause liquid in the nozzle to minutely vibrate; a serial-signal generating unit that can generate a serial periodical signal; a mode-signal generating unit that can generate a mode signal depending on the liquid supplied to the nozzle; and a micro-vibrating controlling unit that can cause the micro-vibrating unit to operate, based on the serial periodical signal and the mode signal.
Particularly, the invention is a liquid jetting apparatus comprising: a head member having a nozzle, a micro-vibrating unit that can cause liquid in the nozzle to minutely vibrate; a micro-vibrating-signal generating unit that can generate a common micro-vibrating signal; a micro-vibrating-mode-signal generating unit that can generate a micro-vibrating mode signal depending on the liquid supplied to the nozzle; and a micro-vibrating controlling unit that can cause the micro-vibrating unit to operate, based on the common micro-vibrating signal and the micro-vibrating mode signal.
According to the above feature, since the micro-vibrating controlling unit can cause the micro-vibrating unit to operate based on the common micro-vibrating signal and the micro-vibrating mode signal, even if the common micro-vibrating signal is used, micro-vibrating operations suitable for the liquid can be achieved by generating the micro-vibrating mode signal dependently on the liquid.
For example, the micro-vibrating-mode-signal generating unit may be adapted to generate a micro-vibrating mode signal depending on a rate of increasing viscosity of the liquid supplied to the nozzle. Alternatively, the micro-vibrating-mode-signal generating unit may be adapted to generate a micro-vibrating mode signal depending on temperature of the liquid supplied to the nozzle.
Preferably, the micro-vibrating controlling unit may have: a signal fusing part that can generate a micro-vibrating operating signal being an AND signal of the common micro-vibrating signal and the micro-vibrating mode signal, and a main controlling part that can cause the micro-vibrating unit to operate based on the micro-vibrating operating signal. In the case, a signal processing based on the common micro-vibrating signal and the micro-vibrating mode signal can be achieved more easily.
In addition, preferably, the common micro-vibrating signal is a periodical signal of a period including a predetermined waveform, and the micro-vibrating mode signal is a periodical signal of a same period as the common micro-vibrating signal including a or more predetermined rectangular pulses. In the case, the respective signals can be generated more easily.
In addition, in order to achieve the object, the invention is a liquid jetting apparatus comprising: a head member having a plurality of nozzles, the nozzles being classified into at least first and second classes; a micro-vibrating unit that can cause liquid in a nozzle or nozzles of the first class to minutely vibrate and that can cause liquid in a nozzle or nozzles of the second class to minutely vibrate; a micro-vibrating-signal generating unit that can generate a common micro-vibrating signal; a micro-vibrating-mode-signal generating unit that can generate a first micro-vibrating mode signal depending on the nozzle or nozzles of the first class and that can generate a second micro-vibrating mode signal depending on the nozzle or nozzles of the second class; and a micro-vibrating controlling unit that can cause the micro-vibrating unit to operate, based on the common micro-vibrating signal and the respective micro-vibrating mode signals.
According to the above feature, since the micro-vibrating controlling unit can cause the micro-vibrating unit to operate based on the common micro-vibrating signal and the respective micro-vibrating mode signals, even if the common micro-vibrating signal is used, micro-vibrating operations suitable for the nozzle or nozzles of the respective classes can be achieved by generating the respective micro-vibrating mode signals dependently on the nozzle or nozzles of the respective classes.
For example, if at least one of the classes includes a plurality of nozzles, liquid in the nozzles of the at least one of the classes may have a rate of increasing viscosity. Alternatively, if at least one of the classes includes a plurality of nozzles, liquid in the nozzles of the at least one of the classes may be a same kind.
In the case too, for example, the micro-vibrating-mode-signal generating unit may be adapted to generate the respective micro-vibrating mode signals depending on respective rates of increasing viscosity of liquid supplied to the nozzle or nozzles of the respective classes. Alternatively, for example, the micro-vibrating-mode-signal generating unit may be adapted to generate the respective micro-vibrating mode signal depending on respective temperatures of liquid supplied to the nozzle or nozzles of the respective classes.
In the case too, preferably, the micro-vibrating controlling unit may have: a signal fusing part that can generate respective micro-vibrating operating signals being AND signals of the common micro-vibrating signal and the respective micro-vibrating mode signals, and a main controlling part that can cause the micro-vibrating unit to operate based on the respective micro-vibrating operating signals.
In addition, preferably, the common micro-vibrating signal may be a periodical signal of a period including a predetermined waveform, and each micro-vibrating mode signal is a periodical signal of a same period as the common micro-vibrating signal including a or more predetermined rectangular pulses.
For example, the common micro-vibrating signal may be a periodical signal of a period including a middle trapezoidal pulse and a large trapezoidal pulse, which appear at substantially regular intervals.
Further preferably, the micro-vibrating-signal generating unit may have: a temperature-detecting part that can detect temperature of the head member; a signal-determining part that can determine an amplitude and a waveform of the common micro-vibrating signal, based on the temperature of the head member detected by the temperature-detecting part; and a signal-generating part that can generate the common micro-vibrating signal determined by the signal-determining part.
The liquid may be ink, and the head member may be a recording head.
A computer system can materialize a controlling unit including: micro-vibrating-signal generating unit that can generate a common micro-vibrating signal; a micro-vibrating-mode-signal generating unit that can generate a micro-vibrating mode signal depending on the liquid supplied to the nozzle; and a micro-vibrating controlling unit that can cause the micro-vibrating unit to operate, based on the common micro-vibrating signal and the micro-vibrating mode signal.
Similarly, a computer system can materialize a controlling unit including: micro-vibrating-signal generating unit that can generate a common micro-vibrating signal; a micro-vibrating-mode-signal generating unit that can generate a first micro-vibrating mode signal depending on the nozzle or nozzles of the first class and that can generate a second micro-vibrating mode signal depending on the nozzle or nozzles of the second class; and a micro-vibrating controlling unit that can cause the micro-vibrating unit to operate, based on the common micro-vibrating signal and the respective micro-vibrating mode signals.
This invention includes a storage unit capable of being read by a computer, storing a program for materializing the controlling unit in a computer system.
This invention also includes the program itself for materializing the controlling unit in the computer system.
This invention includes a storage unit capable of being read by a computer, storing a program including a command for controlling a second program executed by a computer system including a computer, the program is executed by the computer system to control the second program to materialize the controlling unit.
This invention also includes the program itself including the command for controlling the second program executed by the computer system including the computer, the program is executed by the computer system to control the second program to materialize the controlling unit.
The storage unit may be not only a substantial object such as a floppy disk or the like, but also a network for transmitting various signals.
In addition, the invention is a liquid jetting apparatus comprising: a head member having a nozzle; a pressure-changing unit that can change a pressure of the liquid in the nozzle; a main-signal generating unit that can generate a jetting-operating signal; a main-mode-signal generating unit that can generate a main mode signal depending on jetting data and the liquid supplied to the nozzle; a signal fusing part that can generate an operating-pulse signal being an AND signal of the jetting-operating signal and the main mode signal; a main controlling part that can cause the pressure-changing unit to operate based on the operating-pulse signal; wherein the jetting-operating signal is a periodical signal of a period including at least two trapezoidal pulses for performing mid-jetting micro-vibrating operations and at least one waveform for jetting a drop of the liquid; and the main mode signal is a periodical signal of a same period as the jetting-operating signal including a or more predetermined rectangular pulses.
According to the feature, since the main mode signal is generated based on the liquid supplied to the nozzle and the operating signal is formed by an AND signal of the jetting-operating signal and the main mode signal, mid-jetting micro-vibrating operations can be suitably achieved correspondingly to respective characteristics, kinds or states of the liquid.
For example, the main-mode-signal generating unit may be adapted to generate a micro-vibrating mode signal depending on a rate of increasing viscosity of the liquid supplied to the nozzle. Alternatively, for example, the main-mode-signal generating unit may be adapted to generate a micro-vibrating mode signal depending on temperature of the liquid supplied to the nozzle.
In addition, the invention is a liquid jetting apparatus comprising: a head member having a plurality of nozzles, the nozzles being classified into at least first and second classes; a pressure-changing unit that can change a pressure of liquid in a nozzle or nozzles of the first class and that can change a pressure of liquid in a nozzle or nozzles of the second class; a main-signal generating unit that can generate a jetting-operating signal; a main-mode-signal generating unit that can generate a first main mode signal depending on jetting data and the liquid supplied to the nozzle or nozzles of the first class and that can generate a second main mode signal depending on jetting data and the liquid supplied to the nozzle or nozzles of the second class; a signal fusing part that can generate respective operating-pulse signals being AND signals of the jetting-operating signal and the respective main mode signals; and a main controlling part that can cause the pressure-changing unit to operate based on the respective operating-pulse signals; wherein the jetting-operating signal is a periodical signal of a period including at least two trapezoidal pulses for performing mid-jetting micro-vibrating operations and at least one waveform for jetting a drop of the liquid; and each main mode signal is a periodical signal of a same period as the jetting-operating signal including a or more predetermined rectangular pulses.
According to the feature, since the respective main mode signals are generated based on the liquid supplied to the nozzle or nozzles of the respective classes, mid-jetting micro-vibrating operations can be suitably achieved correspondingly to nozzle or nozzles of the respective classes.
For example, if at least one of the classes includes a plurality of nozzles, liquid in the nozzles of the at least one of the classes may have a rate of increasing viscosity. Alternatively, if at least one of the classes includes a plurality of nozzles, liquid in the nozzles of the at least one of the classes may be a same kind.
In the case too, for example, the main-mode-signal generating unit may be adapted to generate the respective micro-vibrating mode signals depending on respective rates of increasing viscosity of the liquid supplied to the nozzle or nozzles of the respective classes. Alternatively, for example, the main-mode-signal generating unit may be adapted to generate the respective micro-vibrating mode signals depending on respective temperatures of the liquid supplied to the nozzle or nozzles of the respective classes.
Preferably, the at least two trapezoidal pulses for performing the mid-jetting micro-vibrating operations may include a middle trapezoidal pulse and a large trapezoidal pulse.
Further preferably, the main-signal generating unit may have: a temperature-detecting part that can detect temperature of the head member; a signal-determining part that can determine an amplitude and a waveform of the jetting-operating signal, based on the temperature of the head member detected by the temperature-detecting part; and a signal-generating part that can generate the jetting-operating signal determined by the signal-determining part.
The liquid may be ink, the head member may be a recording head, and the jetting data may be recording data.
A computer system can materialize a controlling unit including: a main-mode-signal generating unit that can generate a main mode signal depending on jetting data and the liquid supplied to the nozzle; a signal fusing part that can generate an operating-pulse signal being an AND signal of the jetting-operating signal and the main mode signal; a main controlling part that can cause the pressure-changing unit to operate based on the operating-pulse signal.
Similarly, a computer system can materialize a controlling unit including: a main-signal generating unit that can generate a jetting-operating signal; a main-mode-signal generating unit that can generate a first main mode signal depending on jetting data and the liquid supplied to the nozzle or nozzles of the first class and that can generate a second main mode signal depending on jetting data and the liquid supplied to the nozzle or nozzles of the second class; a signal fusing part that can generate respective operating-pulse signals being AND signals of the jetting-operating signal and the respective main mode signals; and a main controlling part that can cause the pressure-changing unit to operate based on the respective operating-pulse signals.
This invention includes a storage unit capable of being read by a computer, storing a program for materializing the controlling unit in a computer system.
This invention also includes the program itself for materializing the controlling unit in the computer system.
This invention includes a storage unit capable of being read by a computer, storing a program including a command for controlling a second program executed by a computer system including a computer, the program is executed by the computer system to control the second program to materialize the controlling unit.
This invention also includes the program itself including the command for controlling the second program executed by the computer system including the computer, the program is executed by the computer system to control the second program to materialize the controlling unit.
The storage unit may be not only a substantial object such as a floppy disk or the like, but also a network for transmitting various signals.